1. Field of the Invention
The present invention relates to a combination of a projector using a liquid crystal display (LCD) and a video tape recorder (VTR), and more particularly to a VTR equipped with a color LCD projector.
2. Description of the Prior Art
Today, LCD projectors are widely used as application of LCDs. Since the cost per inch of a screen is high, an LCD projector for a large screen is very expensive. As a result, such an expensive large screen type LCD projector is mainly used only for business purposes. Moreover, most of large screen type LCD projectors have a fixed type construction, not a portable type, because they require a large lens size.
Mainly, compact LCD projectors of the portable type are commercially available. Such a compact LCD projector allows the user to view an image photographed by a video cassette recorder equipped with a camera integral therewith on a trip even when there is no TV by projecting the image onto a wall surface or a screen. Since the compact LCD projector uses a LCD having a size of 0.7 to 1 inch, it is convenient to be carried by the user.
FIG. 1 is a schematic view for explaining operation of an LCD projector. In FIG. 1, the reference numeral 1 denotes a projection lens, 2 an LCD panel, 3 a condensing lens, 4 a reflector, 5 a halogen lamp, and 8 a screen such as a wall surface. Liquid crystal does not emit light by itself and receives light from outside to display a video signal using a variation in reflectivity and transmittivity of a liquid crystal cell. The LCD projector achieves a picture reproduction using a projection of a pattern of light transmitting through the liquid crystal panel 2 on a front surface of the liquid crystal panel 2.
As shown in FIG. 1, light emerging from the halogen lamp 5 as a light source arranged in rear of the liquid crystal panel 2 is reflected by the reflector 4 and then introduced in the condensing lens 3 which, in turn, converts the received light into a parallel light. The reason why all of the light beams incident on the liquid crystal panel 2 are converted into the parallel light by the condensing lens 3 is because in the case of light other than the parallel light, the transmittivity thereof may be varied in the liquid crystal panel 2.
The parallel light incident on the liquid crystal panel 2 is then subjected to a spatial modulation appropriate to video signals. The light which has been subjected to the spatial modulation then enters the projection lens 1 which, in turn, projects the light onto the screen 8 arranged in front of the projection lens 1, so that a picture is displayed.
FIG. 2 is a perspective view of the appearance of the LCD projector having the arrangement of FIG. 1. In FIG. 2, the reference numeral 1 denotes the projection lens shown in FIG. 1, 7 a focusing ring, and 10 a cassette insertion/extraction opening of a VTR. The LCD projector of the illustrated type is commercially available in the form of a single product to be used as an exclusive unit for the projection.
As shown in FIG. 2, various wirings such as couplings and power supply lines are connected between the LCD projector and the VTR. When such wirings are reduced in number, a convenience in use is improved. On the contrary, where the wirings are increased in number or in length; a degradation of video signals may easily occur due to generation of noise. In the latter case, processes of separating and composing video signals between the appliances are increased in number, thereby causing the signals to be easily degraded.
On the other hand, a compact LCD projector is frequently used for reproduction of VTR. In this case, the LCD projector should have wirings for video signals to be supplied from the VTR. Wirings for audio signals and electric power should be also provided. As a result, the above case encounters the complexity of wirings. Where the LCD projector is integral with the VTR in order to eliminate the complexity of wirings, a convenience in use is obtained.